On the other hand, there are also disadvantages... For example the people become anti-social because they are only using their phones and they don't talk with the people they have around. The smartphones are so expensive too, the prices are exagerated! Smartphones steals a lot of time above all the teenagers time who are addicted at their phones. And the last disadvantage are the hackers. They are people who can make a lot of damage in the life of the other people, for me it is the worst disadvantage.
In conclusion, I think that smartphones are good for the people if they are using it correctly and with good intentions.